Holographic Dark Energy Model Research Articles

Physical Acceptability of the Renyi Holographic Dark Energy Model Under the Hubble's Cutoff in f (T, B) Gravity

Physical Acceptability of the Renyi Holographic Dark Energy Model Under the Hubble's Cutoff in f (T, B) Gravity

New Tsallis holographic dark energy with Granda–Oliveros as IR-cutoff

In the current study, a theoretical model for non-interacting new Tsallis holographic dark energy is constructed using the Granda–Oliveros as the IR cutoff with specified scale factor [Formula: see text]. The time-dependent deceleration parameter, with appropriate assumptions, yields this scale factor. The features of the deceleration parameter, equation of state parameter, density parameter, and jerk parameter are then investigated for this model. According to our findings, the cosmos has a normal thermal history, dark matter and dark energy eras occurring one after the other until dark energy eventually takes over entirely in the far future. Additionally, the evolution of the potential and pressure to indicate the universe’s accelerated expansion by using our model are studied. We investigate the evolution trajectory of statefinder parameters, which is consistent with ΛCDM model.

Barrow's holographic dark energy model in axially symmetric space-time

Barrow's holographic dark energy model in axially symmetric space-time

Reconstruction schemes of scalar field models for the Power Law Entropy Corrected Holographic Dark Energy model with Ricci scalar cut-off

In this work, we examine the cosmological characteristics of the Power Law Entropy Corrected Holographic Dark Energy (PLECHDE) model with infrared (IR) cut-off, which is determined by the curvature parameter k, the time derivative of H, and the average radius of the Ricci scalar curvature R, which varies with the Hubble parameter H squared. We obtain the deceleration parameter q and the Equation of State (EoS) parameter of Dark Energy (DE) ωD. Additionally, we derive the Hubble parameter H and the scale factor a expressions as functions of the cosmic time t. Additionally, we examine the limiting scenario that pertains to a flat Dark Dominated Universe. Furthermore, we establish a correspondence between the DE model considered and some scalar fields, in particular the Generalized Chaplygin Gas, the Modified Chaplygin Gas, the Modified Variable Chaplygin Gas, the New Modified Chaplygin Gas, the Viscous Generalized Chaplygin Gas, the Dirac-Born–Infeld, the Yang–Mills, and the Non Linear Electrodynamics scalar field models.

Integrated study of dark matter and dark energy models

Dark matter and dark energy are used as two important concepts in cosmology to explain some of the observed phenomena in the universe. Dark matter is one of the most dominant constituents of the Universe, and it influences the structural formation of the Universe through gravity, including the formation and evolution of galaxies, clusters, and the large-scale structure of the Universe. Dark energy is believed to be one of the causes of the accelerated expansion of the Universe, and its presence explains the observed phenomenon of the accelerating rate of expansion of the Universe. Although their existence has not been directly observed, people understand through the study of the structure and evolution of the universe that they play an important role in the universe. This paper first introduces the background knowledge of dark matter and its related properties and explains the reasons why three types of models, namely WIMP, axion, and sterile neutrino, are candidates for dark matter in the light of existing observations. The paper then discusses the relevant properties of dark energy and analyses the mainstream dark energy models. For the cosmological constant mode, the fine-tuning problem and cosmic coincidence problem it faces are analysed in detail. The evolution of the dark energy equation of state from the past >-1 to the present <-1 is then explained, and this is used to introduce the scalar field model involving dynamic, the Chaplygin gas model, the holographic dark energy model, and the interacting dark energy model.

Tsallis Holographic Dark Energy with Power Law Ansatz Approach

Holographic principles have proven to be a very interesting approach towards dealing with the issues of the late-time acceleration of the universe, which has resulted in a great amount of work on holographic dark energy models. We consider one such very interesting holographic scenario, namely the Tsallis Holographic dark energy model, and consider an ansatz based approach to such models. We consider three cosmological scenarios in such models, namely those with viscous, non-viscous, and Chaplygin gas scenarios, discussing various crucial aspects related to these models. We discuss various crucial properties of the Tsallis model in such scenarios and see how the phantom divide is crossed in each case, but it is only the Chaplygin gas models which provide a better view on stability issues.The symmetry property of the theory presented in the article is the assumption that space is isotropic. Using bulk viscosity instead of shear viscosity reflects spatial isotropy.

Cosmic implications of Kaniadakis HDE model in Chern-Simons modified gravity

In this study, we investigate the FRW model in the Chern–Simons modified gravity framework, considering holographic dark energy and Kaniadakis holographic dark energy models. Employing the field equation of Chern–Simons gravity, it is analyzed some important cosmological parameters such as density, equation of state, and deceleration parameters for both models. Our findings, presented visually through graphs, reveal that holographic dark energy places the equation of state within ω∈(−1,−0.4), while Kaniadakis holographic dark energy spans ω∈(−0.8,−0.4). These results demonstrate the dynamic nature of dark energy’s influence. Our study highlights the interplay of quintessence and ΛCDM across cosmic eras. We identify the ranges of q∈(−0.89,−0.86) and q∈(−0.9925,−0.9922) for Kaniadakis holographic dark energy and holographic dark energy, offering insights into their roles in cosmic inflation which implies that the universe attributes are impacted by both quintessence and the ΛCDM model in Chern–Simons modified gravity. In addition, this study implies that the universe’s expansion is decelerating in its current state.

Cosmic Aspects of Sharma-Mittal Holographic Dark Energy Model in Brans-Dicke Theory of Gravity

Cosmic Aspects of Sharma-Mittal Holographic Dark Energy Model in Brans-Dicke Theory of Gravity

Rényi holographic dark energy model with two IR cutoffs in Marder type universe

Rényi holographic dark energy model with two IR cutoffs in Marder type universe

An Examination of the General Relativity of the Bianchi type V Holographic Dark Energy Model Using the Hybrid Expansion Law

This examination presents an investigation of the qualities of anisotropic and homogeneous Bianchi type V space-time inside the setting of general relativity, while considering the consideration of dark matter and holographic dark energy model parts. The arrangements of the differential condition fields have been determined by looking at two unmistakable situations: one where the extension scalar in the model is straightforwardly relative to the shear scalar, and one more where the typical scale factor is expected to follow a half breed development structure. The answers for the field conditions are inferred inside the system of general relativity. A similar to peculiarity was found with regards to the tension and condition of state boundary of the holographic dark energy model inside their separate settings. This study researches the physical and mathematical parts of a few factors that hold infinite importance, including the jerk boundary inside our model. The noticed boundaries line up with the cosmological models that portray the present status of the universe, described by sped up extension. All in all, we state that our model looks very similar to the ΛCDM cosmological model all through the later stages and lines up with the most recent discoveries of cosmological information.

Bianchi Tip-V Evreninde Granda-Oliveros Ölçekli Tsallis Holografik Karanlık Enerji

A wide variety of cosmological observations show us that our universe is in an accelerated expansion phase. Dark Energy and Dark Matter are thought to be two of the causes of this accelerated expansion. Therefore, scientists have recently been doing many studies on dark energy and matter. In particular, many energy density relations are written, and research is done about space-time structure. In this sense, the Tsallis holographic dark energy model is also in a current and interesting position. The study establishes a relationship between the Tsallis holographic dark energy (THDE) model and some scalar fields (quintessence, tachyon, dilaton scalar fields, etc.) specific to the Bianchi-type V space-time model. The relationship above is discussed within the Granda-Oliveros (GO) cut-off framework. The state equation parameter is calculated analytically, and the phase of our universe for this model is investigated with the graphs drawn. In addition, there is how the kinetic energy and the scalar potential change with time. The results are again analyzed numerically with graphs.

Cosmology of new Tsallis holographic dark energy-based reconstructed models in teleparallel theories

Reconstruction of Lagrangian functions present in the action of modified gravity theories is one of the most captivating subjects in recent cosmology. This paper reconstructs the form of Lagrangian function of some teleparallel theories based on a recently proposed holographic dark energy model namely new Tsallis HDE. For this purpose, we assume ordinary matter contents as perfect fluid with background geometry as flat FRW spacetime. On the first place, we reconstruct [Formula: see text] function by taking some well-known IR cutoff choices into account like Hubble radius, event horizon, Granda–Oliveros cutoff and conformal time as different cases. Moreover, we consider two entropy corrected forms of new Tsallis HDE with the simplest choice for IR cutoff. We explore the graphical behavior of different cosmic quantities, e.g. dark energy EoS parameter, the generalized second law of thermodynamics, the null energy condition, speed of sound and trajectories in [Formula: see text] plane for these reconstructed solutions and discuss their viability. Then we extend our work to [Formula: see text] theory and reconstruct the Lagrangian function for new Tsallis HDE with three simple choices of IR cutoff (Hubble radius and event horizon), and Granda–Oliveros cutoff and discuss the significance of obtained solutions graphically through same cosmic measures. It is found that presented models are consistent with the recent cosmic data values, however, stability can be achieved in some certain cases only.

Bianchi type-III THDE quintessence model with hybrid scale factor

The current research investigates the behavior of the Tsallis holographic dark energy (THDE) model with quintessence in a homogeneous and anisotropic Bianchi type-III space–time. We construct the model by using two conditions: ( i) expansion scalar ( θ) is proportionate to shear scalar ( σ) in the model and ( ii) hybrid scale factor a = t βe γt, where β > 0 and γ > 0 are constants. Our study is based on Type Ia supernovae data in combination with CMB and BAO observations (Giostri et al., JCAP 3, 27); the present values of Hubble constant and deceleration parameter are H0 = 73.8 and q0 = −0.54, respectively. Compiling our theoretical models with these data, we obtain [Formula: see text] for [Formula: see text], respectively. We completed an entirely novel form of cosmic model where the expansion occurs during the present accelerated phase for the constraints. We have discussed the conformity among the scalar field model of quintessence and THDE model. To understand the Universe, we have also established the relations for distance modulus, luminosity distance, and angular-diameter distance. Some geometric and physical aspects of the THDE model are also highlighted.

Bianchi Type-V space time with Tsallis holographic dark energy

In this paper, using the framework of Saez–Ballester theory, Bianchi Type-V metric Tsallis holographic dark energy models with interacting and non-interacting elements have been constructed. To obtain solutions for the model, we used correlation between metric potentials and varying deceleration parameters. There is additional discussion of the models’ physical characteristics and behavior.

Cosmic Evolution of Five‐dimensional Einstein Chern‐Simons Gravity Through Dark Energy Model

AbstractIn this paper, the cosmic evolution in the context of five‐dimensional Einstein Chern‐Simons gravity theory by using flat homogeneous and isotropic universe model is studied. The interaction is taken into account between dark sector of the evolving universe along with holographic dark energy model with Hubble horizon. Our study with well‐known models EChS ‐β5 and EChS ‐ for Einstein Chern‐Simons gravity theory in five dimensions are carried. Some cosmological parameters through graphical representations such as coincidence parameter u, equation of state parameter , deceleration parameter q and squared speed of sound parameter is analyzed. It is found that these cosmological parameters show consistent behavior with current cosmic scenario. Also, the behavior of generalized second law of thermodynamics in the underlying gravity theory with Bekenstein‐Hawking entropy and its validity for some fixed values of constants appearing in each model are explored.

Quintessence reconstruction through new Tsallis holographic dark energy model

In statistical theory, the Tsallis entropy is an extended form of the Boltzmann–Gibbs entropy. The dimensionless parameter [Formula: see text] is employed to state the quantitative difference from the standard scenario. The concepts of Tsallis entropy and the future event horizon are employed in formulating the present new Tsallis holographic dark energy (NTHDE) model. The model attempts to explain the properties of dark energy using the foundation of quantum gravity. The differential equation characterizing the evolution of the NTHDE density parameter is obtained. Expressions stating the dynamic behavior such as equation of state (EoS), deceleration and jerk parameters are obtained in terms of the NTHDE density parameter. For [Formula: see text], the quintessence nature of scalar field could completely characterize the NTHDE. A reconstruction of the scalar field’s dynamics and quintessence potential is attempted. We demonstrate that the diagnosis made by statefinder is adaptive enough to distinguish between quintessence and cosmological constant-based dark energy models. Additionally, observational data obtained from CC[Formula: see text] SNIa [Formula: see text] union 2.1 sources are used to evaluate the model’s effectiveness.

Renyi Holographic Dark Energy Model in f(R) Gravity with Hubble's IR Cut-Off

In the present study, a homogeneous and anisotropic LRS Bianchi type-I universe model is considered with an interacting dark matter and Renyi holographic dark energy model (RHDE) in f(R) gravity. The deceleration parameter (DP) shows a signature flipping for a universe which was decelerating in past and accelerating at present epoch. Therefore, the DP is a most physically justified parameter to analyze the solution of cosmological model. In order to find an exact solution of the field equations of the model, the shear scalar is considered to be proportional to the expansion scalar. We have considered f(R) = b Rn, the depiction model of f(R) which is the function of Ricci scalar R. The physical and geometrical characteristics of the universe model have been studied.

Quintessence scalar field of Kaniadakis holographic dark energy model with statefinder analysis

This paper explores the quintessence reconstruction and statefinder perspective of Kaniadakis holographic dark energy model in a flat universe with future event horizon as an IR-cutoff. The cosmological parameters of this model were re-examined from the quintessence behavior aspect. Also we reconstruct, [Formula: see text], the potential of quintessence scalar field, which shows the best fit with joint analysis data of JLA+CC+BAO for the priors [Formula: see text], [Formula: see text]. In the [Formula: see text]–[Formula: see text] phase space, the freezing-tracker model represents our canonical scalar field. This model exhibits quintessence behavior in the statefinder ([Formula: see text]–[Formula: see text]) plane for model parameters [Formula: see text] and [Formula: see text] that are close to [Formula: see text] and [Formula: see text]. The present values of deceleration [Formula: see text], statefinder [Formula: see text], jerk [Formula: see text] and model parameters [Formula: see text] are consistent with the limits of the observational data. Using the distance modulus [Formula: see text], we also fit 580 SN Type I Union2.1 data sets to our model.

Diagnosing Renyi and Tsallis holographic dark energy models with Hubble’s horizon cutoff

Diagnosing Renyi and Tsallis holographic dark energy models with Hubble’s horizon cutoff

Ricci-cubic holographic dark energy

In this work, we propose the Ricci-cubic holographic dark energy model. The model is inspired by the cubic curvature invariant formed by the contraction of three Riemann tensors. A combination of Ricci scalar and the cubic invariant is used to describe the infrared cutoff of the holographic dark energy. Such a construction is extremely useful since the evolution does not depend on the past or future features of the universe, but completely on its present features. Moreover, the use of invariants makes the theory more fundamental in nature. We have constructed the model and studied its cosmological features. The analytical solutions of various cosmological parameters such as the density parameter, equation of state parameter, and deceleration parameter are extracted and their behaviour is studied. It is seen that the holographic dark energy model can exhibit all the cosmological epoch, sequentially starting from radiation in the early universe, followed by matter, and finally the dark energy dominated epoch at late times. The equation of state parameter shows that the model can exhibit quintessence nature, phantom-divide crossing, and even phantom nature depending on the choice of parameter spaces.